Core drill



Dec. 17, 1929.- B. D. THOMPSON CORE DRILL Filed Nov. 17. 1928 ATTORNYSwf @Zag/afm Patented Dec. 17, 1929 UNITED STATES PATENT OFFICE GOREDRILL Application led November 17, 1928. Serial No. 920,182.

The invention relates to core drills for taking samples of earthformations and consists in the features and combination and arrangementof parts hereinafter described and particularly pointed out in theappended claim.

In the 'accompanying drawings Figure 1 is a vertical sectional view ofmy improved drill.

Fig. 2 is a detail view. Fig. 3- is a sectional view on line 3-3 of Fig.1.

Figs. 4 and 5 are detail views. The invention includes a suitable cutter1 adapted to rest on the bottom of the well. This cutter consists of ahollow shell having a tooth formation at its lower end adapted to cuttheformation so as to leave a core of said formation indicated at a of lessdiameter than the interior of the Shell thus leaving an annular channel3 about the core and between it` and the shell 2 for the upflow of thedetritus or so-called sand pumpings as will hereinafter be referred to.

For this ypurpose the teeth of the cutter are wide at their lower endsto cut a path wider than the thickness of the shell to provide theclearance around the core memtioned above, and also to cut clearancearound the outside of theshell and between it and the wall of the holefor the circulation of the detritus or sand pumpings. The cutter shellis attached by screw threads to a tube 3*, which at its upper end isscrew threaded to a block 4 having a vertical bore orport 5 which at itsupper end has a Hap valve 6, secured at 7 so that it may open upwardlyfor the passage of thev detritus up through port 5, but said valveprevents downward 1)assage of material through said port.

L The block 4 has a tube 8 screw threaded the-reto said tube being screwthreaded at its upper end into connection with a block 9 forming a partof a stuffing box 16. Another tubing section 11 is screw threaded to theblock 9 of the stufiing box and this tube section at its upper end isscrew threaded to ahead 12. Within the tubular casing or member 8 apiston 13 is mounted to reciprocate vertically and without unduefriction.

This piston has ports 14 extending verlthrough the head 12. It isprovided at its tically therethrough controlled by downwardly closingvalves 14". The plston rod 15 extends up through the stuffing box andupper end with any suitable means for atu tachment to an element ormeans for reciproeating it such as are usual on the derrick of earthdrilling rigs. At a point near the upper end of the tubing 8 and underthe stuffing box 9 lateral ports 16 are formed through the sa1d tubingfor the discharge outwardly therethrough of the detritus or sandpumpings. In the operation of the apparatus as thus far described,.wewill suppose that rotary step by step movement is given to the tool asit rests upon the bottom of the hole. Means for imparting this rotarymotion will be later referred to. The teeth of the cutter will,therefore, cut the formation, while it mamtains itself by its weightupon the bottom of the hole. During this cutting operatlon the pistonwill be reci rocated vertically by suitable means attac ed to the upperend of the piston rod with the result that the 75 d etritus and sandpumpings will be continuously drawn away' from the teeth of the cutterupV through the annular channel surrounding the core, past valve 6,through the piston and out through the openings 10, so that the cuttingedge will be kept clear of cuttings and will perform its cutting actionon the virgin formation instead of yreacting on the detritus alreadyproduced by the cutting teeth. This flow of the detritus will be due tothe action of the piston which when it goes up will draw the material uppast valve 6, at the same time forcing out through the ports 10 anymaterial which lies above it. On the down stroke the valve 6 will closeand the piston valves will open allowing the material to get above thepiston so that on the next A upstroke of the piston the material will beforced out through the ports 10. In this way the cutting teeth areconstantly cleared of cuttings thus enabling lthe teeth to act directlyon the formation to be out with eficiency. I

The lateral openings 10 lie above the upper limit of movement of thepiston so that they Ag c Y 1,739,928

are always free for the discharge of material therethrough.

I stated above that the tool may be rotated by any suitable means. Inthe form of my invention, which I have chosen for its illustration, Iemploy teeth :v on the interior of the head 12 to be engaged by pawls ypivotally mounted at e in adisc A and arranged when the disc is rotatedone way tov cause the pawls v lo by engaging the teeth to rotate thehead and the tubin and cutters. This disc has a pin 18 exten ng into agroove 17 in the piston rod.. Said groove extends spirally of the rodand as the rod moves up` and down it rotates the'disc irst one way andthen the other by the walls of the groove acting as cam surfaces againstthe pin 18. When the disc rotates one way it turns the apparatusthroughthe pawl and ratchet connection, and

g0when the disc turns in the other direction the pawls ve or turn-ontheir pivots and move along ie inner side ofthe head without rotatingit. The pawls thus engage new teeth and on the next forward movementthey turn as the head together with the tubing and cutter another stepforwardly. It will be noticed that the ratchet mechanism is located inthe cavity of the head member 12 above'a block 2O fixed on the interiorofthe tubing.

$0 On the piston rod at a point above the stuing box a collar orenlargement 21 is 1ocated. When the apparatus isto'be withdrawn from thewell the piston rod is raised until the collar strikes themember I sey86 lcured within the tubing and then continued upward movement of thepiston rod will draw the apparatus out of the well.

' At b I show grips representative of any suitable form for grasping thecore and breakl 40 ing and lifting it when the apparatus is drawn up outof the well.l I claim:

In combination a tube having teeth at its lower end to out the formationat the bottom 5 vof the hole when the tool is rotated, a block withinthe tube having a Apassage therethrough for the upilow of fluid anddetritus, a valve closing downwardly and controlling said passage, astuiing box in the tube above y said block, apiston working in the tubeinter'- mediate of said block and stuing box, said piston havin valvemeans to permit upward flow of the uid and detritus, and to raise saidfluid and detritus, said tube having a 56 discharge port leadingto theoutside oftheI said tube at a point below said stuiiing box and abovethe piston when lowered, a piston rod extending up from the piston andthrough 'the upper part of the tube andl means for ro- Q6 tating thetube, said -means being operated from the reciprocations of the pistonrod, substantially as described.

' In testimony whereof I aix my signature v BURCHARD D. THOMPSON

